Milling machine



SepLf}, 1945. 4 v R. L. ROUGEMONT ETAL- 1, 8

MILLING MACHINE Filed April 10; 1942 Sheets-Sheet 2 INVENTORS.

" RENE LOUIS ROUGEMONT ATTORNEY Sept. 4, 1945. R. L. ROUGE MONT I II AL 8 MILLiNG MACHINE Filed April 10, 1942 4 Sheets-Sheet 3 'INVENTORS RENE LOUIS ROUGEMONT & JAMES s.wu sou ATTORNEY p 1945- R. L. ROUGEMONT grAL 2,384,133

' MILLING MACHINE- I Filed April 10, 1942 4 Sheets-Sheet 4' INVENTORS RENE LOUIS RousEM T & JAMES B.WILSON ATTORNE Patented Sept. 4, 1945 MILLING MAcniNE Ren Louis Rougemont and James B. Wilson, Worcester, Mass., assignors to Reed-Prentice Corporation, Worcester, Mass. a corporation of Massachusetts Application April 10, 1942, Serial No. 438,422

8 Claims. (01. 9021.5)

The present invention relates generally to machine tools, and more particularly to improved mechanism for actuating and controlling the movements of the work support and cross slide of a horizontal milling machine Fig. dis a schematic view, illustrating the A general object of the invention is t provide interlock between the manual and automat c improved means for controlling movements of 9 1 and related portlons of the hydrauhc the work support and cross slide through fluid clrculth pressure operated mechanism, to permit of con- Flgs- 1 3 are fragmentary'vtews' lnustrat' venient control of both elements at feed and 10 mg detatls'of the conltml mechamsmsf traverse speeds through various operating cycles, R'eferrmg t t 1 2 Invention both manually and automatically. l"? as bemg embodied machine Another object of the invention is to provide m t bed upon whml} 1S formeqspaced in a milling machine of the above indicated type, honzontal ways 2 for supporpmg and guldmg a pair of members conveniently disposed for hand workfiable The table adapted to have operation, whereby both the speed and direction reclprocatory' mqvement lmparted tfhereto on of movement of the work support and cross slide the ways by mea-ns of a lotaltably dnven scr'ew shaft 4 movable with the table and cooperating can be manually controlled through functlonlng with a mu 5 carried by the bed as indicated in of the fluid pressure operated dnvmg means, mdotted lines in Fig The means f controlling gepgndently of the autpmatlc control of the same the speed and direction of rotation of the shaft 4 riiiiiiifii fiaii1 3 23123 leiiiii fifvfifniii 1 f i, d d a t d between the work and tool, preparatory to taki ht g g e g a; i en ing a out without the expenditure of any phys-' mg a a We I e a 8 ways ical efiort, other than that required to manipu-' and a cross shde 1 1S movable back and firth late the control handles. Provision is also made ways 6 by means of a rotatably d-nven screw shaft .8. ,The frontof .the cross slide 1 gar complete hand control independently of the providesspaced vertical ways 9, on hi h a tool ower means.

Another object of the invention is'to provide i ig 'gfafi y gxgfi gf x ggg l l 21 2 152? interlocking arrangement between the head 1:0 provides ,a tool spindle l2, adapted to be 252531? ii ti iiuii tisiii? iiiiaiii iirivifig drive were Speeds by means motor for either the work supports or cross slide i fgga a f m and movable Wlth the 1s cfmtrfllled lf P a manual 9 automatic The essential elements of the milling machine basls, W t p h y o nf m the ndescribed 'thusfar are usual in machines of this trO s. That is o y, the automatic Q manual character, and the present invention has to do controls for each power unit functioning entirely improved mechanism for ontrolling moveindependently of each other, to the extent that mer ts bf the table and cross slide I, to cause either the work table or cross slide can be caused 40 a, tool mounted on the spindle 12 to perform the to travel at a desired speed and direction, under desired cutting operation on work mounted on manual control, entirely irrespective of the exthe table. As will hereinafter appear, this conisting speed adjustment of a unit. trol is such as to provide for either the feed or The above and other advantageous features rapid traverseof both tool and work through of the invention will hereinafted more fully apvarious operatingcycles, both manually and aupear from thefollowing description considered in tomatiqally, with all controls being readily connection with the accompanying drawings, in ac cessible'to the operator. W1113h-- I Referr n now to Fig. 4, there is shown a' de- Fig. 1 15 a view in front elevation of a machine velopment in perspective of the manual and auem iody the c ntomatic controls for the work table 3 and cross 1 1g. 2 1s a plan view of the machine shown in slide 1, which are indicated in dotted lines only, Fig. 1. to show the relative positions of the parts. As

Fig. 3 1s a side elevation of the machine shown will beevident from a comparison between Figs. in Fig. l, as viewed from the right. 7 1 and 4,, these controls are mounted on thefront F1g. 4 is a development in perspective of the manual and automatic controls for the power units.

Fig. 5 is a view partially in section of one of the power units.

of the bed I, which provides suitable panels l3 oil to a fluid motor of the same type. The par.

ticular power unit employed is of the general" type commercially known as the Sundstraridfoil power transmission, and so need not be de- 7 scribed in detail at this point, other than to state that each unit [5 or IE provides an input shaft I! for the pump, and an output shaft 18 for the motor, hereinafter termed the motor shaft. The

power unit l5 and I6 are driven in -unison through suitable gearing I9 from an electricmotor located inside a vertical portion fa of the bed, which provides-the ways 6 for the cross slid see Fig.3. Since the power transmission units l5 and 16 are identical in construction and in operation, the manner of controlling the speed and direction of rotation of the output shaft of each: unit isdescribed in detail only with reference to the motor shaft I8, which is connected to the-tablefeed screw shaft 4, as shown in dotted lines in Fig. 3. Referingto Fig. 5, the power unit 15 is shown with a portion ofits control housing 21 in section, with-a control stem 22 extending in the direction of the right-hand panel I3 on the machine .bed I. This stem 22 is movable longitudinally from the neutral position shown, to produce rotation of the motor shaft H3 in opposite directions. That is to say, when the stem is pulled out, clockwise rotation of the shaft I8, as viewed in Fig. 4, is produced; when the stem is pushed in, counterclockwise-rotation results, With'the shaft l8 being stationary whenthe stem 22 occupies a neutral or intermediate position.

The control mechanism also comprises rack plungers 23 and 24 connected by a pinion .25 turnable with a shaft 2-5. Normally, the plungers 23 and 24 are movable by hydraulic pressure, ad-

mitted to-the -rackcylinders by the above described shifting of the stem 22, eithenin or out. To operate the motor shaft l8 ina given direction, pressure is admitted to one of-the 'raek'cylinders to move one of the plungers from .the neutral position shown, which'has the efiect of turning the pinion shaft 26 in one direction or the other, in accordance with whether the stem 22 is moved in or out and thereby move the other 'plunger in the opposite-direction. 1 I

the length of the strokes-of the pump'andmotor pistons, .which are depended upon to transmitsthe power. from the input shaft H to the output shaft I8.

Referring again to Fig. 4, the'control stem 22 is connected by a link 30 to 'atwo-arm lever 3L: which is in turn connected-by a link 32-to an arm. 33 one shaft: 34, rotatably supported '34 extends through the panel by the bed I below the table ways 2. The shaft l3, and carries at its end an operating handle 35. The linkage connecting the shaft 34 to the stem 22 is such that turning of the handle 35 will move the stem 22 in or out to cause rotation of the motor shaft i8 in one direction or the other, to thereby move the work table 3 through rotation of its feed screw 4.

The speed at which the table will move is determined by a knob 36 mounted on the end of ashaft 31 extending through the panel l3, and connected by couplings 38 and a link 39 to a the speed of the motor shaft l8, and consequently the rate of table feed, can be readily controlled by the knob 35, which is closely adjacent the table control handle 35,. see Figw 1.

The handle 35 is shown in its neutral position in Fig- 1, in. which position. the connecting linkage maintainsthe control stem ;22 in its neutral position, with the motor shaft I78. stationary. By turning the handle 35 to the rig-ht or left feed position,- the table3 is caused to move to the right or left at a rate determined, by theprevious setting of the speedcontrol knob 36. The extent to which the table moves tothe right or left, in accordance with the feed position of the handle 35, is determinedby the setting of dogs 43 movable with the table, which are adapted to engage a lever 44- turnable with a shaft 45 extending beneath the table. The shaft; islconnected by an arm 46 andlink 41 toan arm 48 mounted on the inner end. of the shaft 34. Consequently, when the table reaches either end of the stroke for which te dogs 43 are set, the lever 44 will be turned to automatically cause stoppage of the table through the resulting movement of the control stem 22 to its neutral position. 7

Should it be desired to move the table at a rapid rate, for purposes of traversing, the handle 35 is moved to either one of two extreme positions,

to the right and to the left of the feed positions previously described. When the handle 35 is so moved, the stem 22 is moved to one extreme position or the other, whereby to operate a clutch (controlling gearing surrounding the shaft l8) and thereby step up the speed of the motor shaft l8independently of the setting of the speed adjusting shaft 21. .This mode of operation is inherent in the construction of the control mechanism of the transmission unit I5, and will'be described later with reference to Fig. 6, r

' As previously pointed out, the invention also contemplates the provision. of a manual control for the work table that may be operated independently or the automatic control of the table, as determined by different positions of the handle 35. To this end, a handle 49' is provided on the panel 13', this handle 49 being in the form of an open grip extending somewhat above the table '3, where it may readily be held by the fingers of the operator. The handle 49 is pivotally mounted on a hub 5fl,'secured to the end of a shaft 5| rotatably mounted in a bracket 52 extending upwardly'from the front of the panel [3, see Figs. 3 and 7; I The shaft 5| carries a sprocket 53 connected by a chain 54 to a sprocket 55 forming part of a sleeve 56, freely -turnable on-the shaft 34 on which is mounted the automatic feed handle 35. The sleeve 56 provides a lateral arm 51 conmission unit l5. Therefore, with the stem 22 in.

nected by a link 58 that is supported for vertical movement in a bracket 59. The lower end of the link 58 is connected by a pin 60 to a lever 8| which extends from a hub 62, freely turnable on a shaft 63 extending at right angles to the shaft 34. The hub 62 provides a clutching element 62a which is adapted to cooperate with a clutching element 64 turnable with the shaft'63, and turning movement of the lever 6| by the handle 49 is imparted to the shaft 93 only when these clutch elements are engaged, see Fig. 6.

The end of the shaft 63 carries an arm 55 that is connected by a link 66 to the end of an arm 6! mounted on an extension of the shaft 25 carrying the pinion 25, which serves to connect the rack plungers 23 and 24 for movement in unison, although in opposite directions. Assuming that the feed control handle 35 and consequently the control stem 22 are in neutral position by reason of the connections previously described, and that the clutching elements 62a and 64 are in engagement, it is evident that turning of the handle 49 will cause the pinion shaft 26 to be turned independently of the control stenf 22. The resulting movement of the rack plungers 23 and 24 in one direction or the other will therefore cause the motor shaft I8 to move the table to the right or to the left, in accordance with the direction of movement of the handle 49.

In order to prevent movement of the table 3 by the handle 49 during movement of the table under control of the handle 35, as during work feed, the arm 6| is always unclutched from the arm 65, except when the handle 35 is in its neutral \position, as will later appear. Therefore, movements of the arm 61 in response to turning of the shaft 26 through movement of the control stem 22, are not transmitted to the manual control handle 49. For the same reason, accidental turning movement of the handle 49 during feed or traversing of the table under control of the handle 35, will have no efiect on the operation of the power transmitting unit.

Referring now to Fig. 6, there is shown a schematic layout of the automatic interlock between the handles 35 and 49, to prevent their simultaneous control of table movement, as well as the hydraulic connections for control of the power transmission unit, in the manner outlined above. In this layout, the control stem 22 is shown in its neutral position, whereinthe end of a plunger 68 is yieldingly maintained in a notch 69 provided in a collar 10 mounted on the stem 22. Theopposite end of the plunger 68 carries a bridging member H, which is maintained out of engagement with one pair of spaced contacts 12, while in engagement with a second pair of contacts 13. Upon movement of the stem 22 in either direction to move the table 3, the plunger will be forced out of the notch to open the contacts 13 and to close the contacts 12, the contacts remaining in this condition as long as the stem 22 is in any position other than its neutral position.

Conductors from the contacts 12 and 13 are adaptedto be energized from a suitable source of electrical energy, as indicated, and a solenoid 74 controlling the clutching elements 62a and 64 is connected in circuit with the contacts 72. A second solenoid 15 is connected in circuit with the contacts 13, and this solenoid is adapted to control the position of a plunger 16, forming part of a throw-over valve 11 that is adapted to control the hydraulic circuit of-the power transits neutral position, the solenoid'15 is energized through closure of the contacts 13, with the sole.- noid l4 deenergized through opening of contacts The clutch device, previously described as being disposed between the arms GI and 65, consists of the cooperating clutching elements 62a and 64 normally held in engagement by a spring 18 surrounding one end of the shaft 63. An L-shaped lever 19 provides a pin 19a engaged in a groove provided on the hub 62, while the opposite end of the lever is connected by a link 'to a plunger 8| forming part of the solenoid 14. Consequently, energization of the solenoid 14, with the stem 22 out of its neutral position, will cause the lever 19 to swing to the right, as viewed in Fig. 6, and so disconnect the arms GI and 65 through disengagement of the clutching elements. 0n the other hand, turning of the handle 35 to move the stem 22 into neutral position, will result in deenergizing the solenoid 14 to permit reengagement of the clutch, and resulting control of the rotation and speed of the motor shaft 18 by the handle 49, as will next be described.

As previously pointed out, the solenoid '15 pro vides a plunger 16 forming part of a valve 11 which is connected in the hydraulic control circuit 0f the power transmission unit 15. This control circuit is shown diagrammatically in Fig. 6, and with the solenoid 1.5 in a deenergized condition, the circulation of the hydraulic medium is entirely under the control of the stem 22, so as to determine the direction of rotation of the output shaft l8. Furthermore, with the solenoid l5 deenergized, the setting of the speedcontrol knob 36 determines the speed of rotation of the shaft l8.

However when turning of th handle 35 moves the stem 22 to its neutral position, the resulting energization of the solenoid 15 causes the plunger 16 to move within the valve". Such movement of the plunger 16 causes the opening of two conduits 82 and 83, which allows a plunger This plunger 84 to float within a cylinder 85. 84 forms part of the transmission unit and its normal function is to determine the rate of speed of the output shaft I8 in accordance with the setting of a stud 86 turnable in and out with the speed adjustment shaft 21. However, the establishment of the hydraulic circuit through the conduits 82 and 83 by movement of the valve plunger 16 permits the plunger 84 to float in its cylinder, and thus have no effect on the movement of the rack plungers 23 and 24. That is to say, with the plunger 84 floating in the cylinder 85, the particular setting of the speed control shaft 21 has no effect in limiting movement of the rack'plungers 23 and 24, as the latter may be actuated through turning of the pinion 25 by the shaft 26. Furthermore, when the solenoid 15 is energized, the position of the plunger 16 in the valve 11 is such as to block the several conduits that are used for starting, stopping and reversing the shaftrl8 during normal operation of the unit under the control of the handle 35 and stem 22, thereby rendering'these conduits inoperative during manual control of the unit by the handle 49.

Therefore, with the stem 22 in its neutral position, and with solenoid l5 alone energized through closed contacts 13, complete control of the direction and speed of movement of the.

table 3 is obtainable through the handle 49. By

turning the handle 49 to the right through a small angle, the table 3 will be caused .to move.

to the right at a lowspeed, which can be increased by turning the handle farther to the right. The range of speed obtainable by movement of the handle 49 is the speed range normally obtainable within the power unit I5, by turning the elements 28 and 29 into different angular relations with respect to the input and,

output shafts I1 and I8;

Upon release of thehandle 49 after causing the table 3 to be moved a desired amount, the handle will return automatically to its neutral position, by reason of the equalization of pressure on the rack plungers 23 and 24. The table 3 will then cometo rest as the handle 49 returns to its neutral position, by reason-of the fact that the motor shaft I8 is stationary, with the rack plungers 23 and 24 occupying the position of Fig. 5.. However, as soon as the operator turns the handle 35 to cause feeding movement of the table by shifting of the control stem 22, the handle 49 is unclutched from the rack pinion shaft 26 through reenergization 'of the solenoid M, as previously described. The table movement is then entirely under the control of the handle 35, and any accidental turning of the handle 49 will have absolutely no effect upon operation of the power transmitting unit, due to the fact that lever arms GI and 65 are then disconnected by the disengaged clutch elements 62a and 84.

As previously pointed out, movement of the cross slide 1 with respect to the table 3 is adapted for manual and automatic control, in substantially the same manner as described with referenoe to the table. As best shown in Fig. 3. the second power unit I9 provides an output shaft 87 connected by a coupling 88, gearing 89 and a vertical shaft'99 to the screw shaft 8 extending control of this unit I6 will next be described with reference to Figs. 4 and 8, which show opposite ends of the unit.

The control stem 92 for the unit I6 is connected by means of an arm 93 to one end-of a rock shaft 94, the other end of which provides an arm 95 connected bya vertical link 96 to the end of a lever 91. v turn with an operating shaft 98, which extends directly through the control panel I4, in substantially the same horizontal plane as the shaft 34 carrying the feed control handle 35 for the table 3'. The end of the shaft 98 carries a handle 99, turning of which is adapted to impart back and forth movement to the stem 92 to control the direction of rotation of the output shaft 81. Thus the handle 99 is adapted to control the direction of movement of the cross slide I by the screw shaft 8, in substantially the same manner as the handle 35 is adapted to control movement of the table 3. The speed at which the cross slide I will move under control of handle 99, is determined by. a knob I99 mounted on the end of a shaft I9I extending through the panel I4, and connected'through a coupling I92 to the speed adjusting stud I 93 of the unit IS.

The handle 99 is shown in its neutral position in Fig '4, in which position its connecting linkage maintains the control stem 92 in its neutral position, with the shaft B'I'stationary. By turning the handle 99 to the right or left feed position, he cross slide 7 is caused to move to the right orleft at a rate determined by the previous set- The lever 97 is mounted to The power unit is ting of the speed control knob I 99. The extent to which the cross slide I moves to the right or left, in accordance with the feed position of the handle 99, is determined by the setting of dogs I94 movable with the slide, which dogs are adapted to engage an actuator I turnable with a shaft I99. The opposite end of shaft I99 provides an arm. I91 connected by a link I98 to one arm of a bell crank lever I99, the other arm of which is connected by a link II9 to an arm III mounted on theshaft 98 beyond the arm 91. Consequently, when the slide I reaches either end of the stroke for which the dogs I94 are set, the

actuator I95 will be turned to automatically cause stoppage of the slide through resulting movement of the control stem 92 to its neutral position.

Should it be desired to 'move the slide 1' at a rapid rate, for purposes of traversing, the handle 99 is moved to either one of two extreme positions, to the right and to the left of the feed c'sitions previously described. When the handle 99 is so moved, the control stem 92 is moved to one extreme position or the other, whereby to operate a clutch, not shown, controlling gearing surrounding the shaft 81, to thereby step up speed of the shaft 81 independently of the setting of the speed adjusting knob I99. This mode of operation is inherent in the construction of the hydraulic control circuit of the transmission unit I6, and since the units I5 and I 9 are identical, the schematic diagram, Fig. 6, is illustrative of the manner, in which the rapid traverse speed is obtained through control of the pressure medium, in the conduits marked Feed and Rapid.

The manual control for the cross slide I is obtained by means of a handle H2 mounted on the panel I4 above the feed control handle 99. The handle H2 is turnable with a shaft II3 connected by sprockets H4 and a' chain I I5 to a sleeve H6 freely mounted on the shaft 98. The sleeve H9 provides an arm II'I connected by a link I I9 to an arm I I9. This arm [I9 is connected to an arm I29 through clutching elements similar to the clutching elements 62a and 54, as shown in Fig. 6. The arm I29 is connected by a link I2I to an arm I22 on the pinion shaft I23 of the unit I6, as shown in Fig. 8;

The clutching elements controlling connection between the arms H9 and I29 are adapted to be moved from engagementby a solenoid, not shown,

the energization of which results from moving the stem 92 out of its neutral position. The. stem 92 functions in exactly the same manner as shown with reference to the stem 22 in Fig. 6, to clutch the arms H9 and I29 together, with resulting control of the speed and direction of movement of the slide 1 being then determined entirely by movement of the handle H2. Since deenergiza tion of the solenoid controlling the clutching elements or the arms H9 and I29 is accompanied by energization of a solenoid valve similar 'to the valve 11 in Fig. 6, the unit I6 behaves in the same manner as the unit I5, insofar as complete control thereof by the handle H2 is concerned.

In order to move the tool slide 1 by hand power alone, independently of the power unit IS, a shaft I24 is provided in the panel 14, the end of which is squared to receive a suitable crank I25, indicated in dotted lines. This shaft extends inwardly beneath the table, and is provided at its end with a sprocket I 26 connected by a chain I-2'I to a similar sprocket I28 mounted on the forward. end of the feed screw 8 for the slide 1.

Turning of the. shaft [.24 pe'rmitsmovementyof the slide entirely by hand power, it being noted that the output shaft 81 .of the unit [6 is free to rotate in either direction, with the handles 99 and H2 in neutral position. A similar shaft end I29 is provided in the panel l3 for moving the table 3 by hand power, the shaft being connected by suitable gearing, not shown, to thetable feed screwl. .w 1

From the .foregoing, it is apparent that by the present invention there isprovided an improved control mechanismior amachine'tool' of the milling machine type, whereby both the'speed and direction of movementof the work support and cross slide for a tool'can .bemanually controlled speed motor'connectedto said driving element, a motor control member movable from a stop position for determining the direction r move- A set rates, and a third motor control, member,

through functioning of the driving means, in-" dependently of the automatic control of the same driving means. Furthermore, the control is characterized by an interlocking arrangement between manual and feed control handles, whereby operation of the drivingmotor for eitherthe' table or cross slide is controlled wholly ion a manual or automatic basis. .This interlocking arrangement is such thatwith the automatic control handles 35 and 99 in neutral positionas shown in Fig. 1, the operator can graspboth manual control handles. and .112. to cause movements of the table 3 and cross slide 1 in either direction and at speeds directly determined by the degree of turning of these handles. That is to say, the table 3 can be caused to move very slowly while the cross slide 1 is moved at a much greater rate, or vice versa, with the rate of these movements being entirely independent of the set-tin s of the speed control knobs 36 and H30.

When the work table and cross slide have been moved to obtain the desired relation between work and tool preparatory to the beginning of a cut, release of the handles 49 and H2 immediately brings the table and slide to rest, and the handles 49 and I I2 return to the neutral position shown in Fig. 1. Turning of either feed handle 35 or 99 then causes movement of either the table or cross slide at the particular rate determined by the setting of the corresponding speed control knob 36 or Hill. It is to be noted that as soon as either handle 35 or 99 is turned from its neutral position, the interlock arrangement shown in Fig. 6 automatically unclutches the handle 49 or H2 from the pinion shaft or I23 of the corresponding power unit |5,or l5. Therefore, accidental turning of either manual control handl 49 or 2 with either feed handle 35 or 99 turned from its neutral, or stop, position has absolutely no effect on the operation of the corresponding power unit,

We claim:

1. A milling machine comprising in combination a work table and a tool-carrying cross slide movable at right angles with respect to each other, rotatabl screw shafts for moving said table and slide, separate motors for driving said shafts, pairs of motor control handles for causing said motors to move said table and slide through said shafts in different directions and at difierent set rates, and a manually operable handle for each motor extending above said table for directly controlling operation of each motor and thereby positively determining the direction and rate of movement of either table or cross slide, independently of any existing setting of the first-named speed control handles.

2. A control for machine tools comprising in combination a movable support, a rotatable driving element for moving said support, a variable normally maintained in a neutral position, for determining both theaspeed and direction of movement of. said support by said driving ,element, independently of any setting of said'second named control member, and only when said first named control member occupies its'stop position.

3. A control for machine tools comprisingin combination a movable support, a rotatable. driving element for moving said support, a variable speed motor connected to said'driving element, a motor'control membermovable from a stop, position for determining the direction of movement of said support by said element, a second motor control member for regulating the speed of movement of said support by said element at set rates, and a third motor control member normally maintained inv a neutral position, from which said member is turnable to independently determine the speed and direction of movement of said support by said driving element, whenever said first named control member occupies its stop position.

4. A control for machine tools comprising in combination a movable support, a rotatable driving element for moving said support, a variable speed motor connected to said driving element, a motor control member movable from a stop position for determining the direction of movement of said support by said element, a second motor control member for regulating the speed of movement of said support by said element at set rates, a third motor control member normally maintained in a neutral position, from which said member is turnable to independently determine the speed and direction of said support by movement of said driving element, and means for preventing control of said motor by said third member when said first named control member occupies any position other than its stop position.

5. A control for machine tools comprising in combination a movable support, a rotatable driv-.

' ment of said support by said element, a second motor control member for regulating the speed of movement of said support by said element at set rates, and a third motor control member normally maintained in a neutral position, with displacement of said control member from its neutral position serving to cause the movement of said support by said driving element at a rate of speed independent of the setting of said second named motor control member, and only when said first named control member occupies its stop position.

6. A control for machine tools comprising in combination a movable support, a rotatable driving lement for moving said support, a variable speed motor connected to said driving element, a motor control member movable from a stop position for determining the direction of movement of said support by said element, a second motor control member for regulating the speed of movement of said support by said element at set rates, and a third motor control member normally maintained in'a neutral position, with displacement of said control member from its neutral position serving to cause the movement' of said support by said driving element a't'a rate 'of speed independent of the setting of said second 1 named motor control member, wheneversaid first named control member occupies its stop position, and with said third named control member always returningto it's neutral position upon release thereof.

7. A control for machine tools comprising in:

combination a tool support, a work support, a rotatable driving lement for moving one of said supports relative to the other, a variable speed prime mover connected to said driving element, a

control member for said prime mover movable j from a stop position, for determining the direction of movement of one of said supports by said driving element, a second control member for regulating the speed of movement of said support by said driving element at set rates, and a third control member for said prime mover, turnable from a neutral position, to regulate both the speed and direction of movement of said support by said driving element in accordance with the degree and direction of such turning by said third named control member, independently of any prior setting of said second named control member, and only when said first named control member occupies its stop position 8. A control for machine tools comprising in combination a tool support, a work support, a rotatable driving element for moving one of said supports relative to the other, a variable speed prime mover connected to said driving element, a control member for said prime mover movable from a stop position, for determining the directionof movement of one of saidsupports by said driving element, 'a second control member for regulating the speed of movement of saidsupport by said driving element at set rates, and a third control member for said prime mover, turnab-le -.from a neutral position, to regulate both the speed and direction ofcmovement of said support by said driving element in accordance with the degree and direction of such turning by said third named control member, independently of any prior setting of said second named control member, and interlocking means between said control members for preventing movement of said support by accidental turning of said third control member, while said support is moving under control of said first named member.

' RENE LOUIS ROUGEMONT.

JAMES B. WILSON. 

